Product Overview
Used ICP DAS tM-SG4 CR Adjustable RS-485 Termination Module
This RS-485 termination resistor module is designed for serial networks where signal stability degrades over distance or in electrically noisy environments. It supports controlled biasing and termination across the 485 bus, helping maintain predictable line behavior. A practical tip: adjustable termination is most effective when applied deliberately at physical bus endpoints rather than scattered across the network.
Product Condition
Used. The module was previously installed or in service.
Product Overview
The ICP DAS tM-SG4 CR is a DIN-rail-mounted RS-485 signal conditioning module intended to stabilize long or sensitive serial communication lines. It connects in parallel with the DATA+ and DATA− conductors and provides switch-selectable termination and bias resistors. The module does not process data or act as a gateway; its role is strictly physical-layer conditioning.
Key Features
- RS-485 termination and bias resistor module
- Designed for long-distance or noise-prone RS-485 networks
- 15-step switch-selectable termination resistance
- Termination range approximately 65 ohm to 560 ohm
- Selectable pull-up and pull-down bias resistors
- Bias resistor options of 1 kΩ, 10 kΩ, or 100 kΩ
- Parallel connection to DATA+ and DATA− signal lines
- DIN-rail mount enclosure for control cabinets
Applications
- RS-485 networks with extended cable lengths
- Industrial Modbus RTU communication trunks
- Noise-prone factory automation environments
- Control panels requiring tunable bus termination
- Commissioning and troubleshooting serial networks
- Automation training and bench evaluation setups
Frequently Asked Questions
Does this module implement any communication protocol?
No. The tM-SG4 CR is a physical-layer accessory and does not implement or interpret communication protocols.
Why use adjustable termination instead of a fixed resistor?
Adjustable termination allows impedance and bias to be tuned to real-world cable length, topology, and noise conditions.
Where is this module typically installed?
It is usually placed at one or both physical ends of an RS-485 trunk, depending on network design.
What purpose do the pull-up and pull-down resistors serve?
They bias the RS-485 lines to a defined idle state, reducing false transitions when no driver is active.
You can condition a long RS-485 trunk in a control panel using the adjustable termination resistance, then fine-tune line bias at the DIN rail during commissioning or troubleshooting.
